Model eyes with curved multilayer structure for the axial resolution evaluation of an ophthalmic optical coherence tomography device

Optical coherence tomography (OCT) has been widely applied to the diagnosis of eye diseases during the past two decades. However, valid evaluation methods are still not available for the clinical OCT devices. In order to assess the axial resolution of the OCT system, standard model eyes with micro-scale multilayer structure have been designed and manufactured in this study. Mimicking a natural human eye, proper Titanium dioxide (TiO2) materials of particles with different concentrations were selected by testing the scattering coefficient of PDMS phantoms. The artificial retinas with multilayer films were fabricated with the thicknesses from 9.5 to 30 micrometers using spin coating technology. Subsequently, standard OCT model eyes were accomplished by embedding the retina phantoms into the artificial frames of eyes. For ease of measurement processing, a series of model eyes were prepared, and each contained films with three kinds of thicknesses. Considering the traceability and accuracy of the key parameters of the standard model eyes, the thicknesses of multilayer structures were verified using Thickness Monitoring System. Through the experiment with three different OCT devices, it demonstrated the model eyes fabricated in this study can provide an effective evaluation method for the axial resolution of an ophthalmic OCT device.